Electrical energy storage cells are widely used to provide power to electronic, electromechanical, electrochemical, and other useful devices. An electric double layer ultracapacitor, for instance, generally employs a pair of polarizable electrodes that contain carbon particles (e.g., activated carbon) impregnated with a liquid electrolyte. Due to the effective surface area of the particles and the small spacing between the electrodes, large capacitance values may be achieved. Nevertheless, problems remain. For instance, certain components of conventional ultracapacitors are also sensitive to high temperatures, which may cause leakage of the electrolyte from the capacitor, and in turn lead to reduced capacitance and increased equivalent series resistance (“ESR”). As such, a need currently exists for an improved ultracapacitor.